Gas porting device for a shotgun



Dec. 13, 1960 R. M. CUTTS GAS PORTING DEVICE FOR A SHOTGUN Original Filed July 8, 1948 Fla].

3 A L/l INVENTOR ITTMIVEK United States Patent GAS PORTING DEVICE FOR A SHOTGUN Richard M. Cutts, The Plains, Va.

Original application July 8, 1948, Ser. No. 37,605. Di-

gilsegggnd this application July 15, 1953, Ser. No.

4 Claims. (Cl. 89-14) This invention is a gas porting device for application to the muzzle end of a shotgun barrel, and relates more particularly to a construction wherein the major portions of the gases of explosion passing through the barrel are exhausted to the surrounding atmosphere so that little or no elfect of the remaining gases is had upon the shot and/or powder wads after they leave the barrel, the invention having for a principal object to provide a device which is simple and inexpensive of construction, is readily adaptable to various gauges of shotguns having different barrel lengths without the necessity of making preliminary and expensive research for each individual type of installation, and which will prove highly effective in operation.

This invention relates to the inventive idea as disclosed in my copending application Serial No. 37,605, filed July 8, 1948, and now abandoned, entitled Gas Porting Device for a Shotgun, and of which the present application is a division.

With the foregoing objects in view, together with others which will appear as the description proceeds, the invention resides in the novel construction, combination and arrangement of parts, all as will be described more fully hereinafter, illustrated in the drawings, and particularly pointed out in the claims.

In the drawings:

Fig. l is a vertical longitudinal sectional view taken axially of a gas porting device constructed in accordance with the present invention and illustrating the same as applied to the muzzle of a shotgun,

Fig. 2 is a transverse sectional view taken substantially upon the line 2-2 of Fig. 1 and looking in the direction indicated by the arrows, and

Fig. 3 is a fragmentary longitudinal sectional view of a gas porting device showing a modification in the arrangement of gas ports.

As is pointed out in my copending application to which reference has heretofore been made, it is highly desirable to provide means of simplified nature to exhaust the gases of explosion in directions perpendicular to the horizontal axial plane of the chamber and in diametrically opposite directions in order to bring about balanced porting, and at the same time without detrimentally affecting the forward progress of the shot charge or column as it is discharged from the porting device. This result is accomplished by interposing between the muzzle of the shotgun and a choke device a cylinder in coaxial alignment with both, provided in its upper and lower surfaces with series of ports in precise balanced relationship.

More particularly, the reference character 5 represents the muzzle end of a shotgun barrel, to which is secured a cylindrical member 6 in coaxial alignment with the gun barrel and secured at one end thereto in any desired manher, as by threads 7. The internal diameter of the sleeve or member 6 is either equal to or greater than the bore of the barrel, whereby the axis of explosion issuing from the barrel may have lateral expansion, and the shot column and wads of the charge are free to travel forwardly into and through the choke device represented generally at 8.

2,963,943 Patented Dec. 13, 1960 This choke device may be of any suitable construction, but preferably is made attachable and detachable with respect to the sleeve or member 6 as by screw threads 9, whereby one of several and different devices may be used interchangeably with the shotgun in accordance with the degree of choke desired. This choke device in the present instance is provided with an inner surface which generally tapers forwardly and inwardly toward the throat, said surface at the rear end being directed rearwardly and outwardly to terminate with an enlarged internal diameter, whereby the outermost and laterally dispersed pellets of the shot column will be contactingly received and relatively gently directed inwardly toward the axis of the column in its travel through the device, to the end that a fairly compacted mass of pellets will emerge when the shot column leaves the throat of the choke member.

Whereas in Fig. l the rear portion 10 of the inner surface of the choke device is shown as approximating a smooth curve joining the forward substantially conical surface 11, it is to be understood that the rear portion of said inner surface may be formed as a succession of rearwardly and outwardly diverging conical sections. A front gun sight 12 is shown mounted at the forward end of the sleeve or member 6.

With particular reference to Fig. l, the sleeve or member 6 has its wall provided with a plurality of ports for the lateral escape of the expanding gases of explosion received from the barrel, and the principal object of the present invention is to provide series of spaced ports in the upper and lower portions of the wall of the member to bring about a proper balance in the escaping gases of explosion. In Fig. l, the ports uppermost in the annular wall of the sleeve or member 6 are indicated at 13, while the counterbalance ports in the lower wall of the said sleeve are indicated at 14. These longitudinal series of ports are so formed as to create equal imperforate side wall sections 15 and 16 therebetween as clearly shown in Fig. 2. In other words, the centers of the series of uppermost ports, and the centers of the series of lowermost ports, will lie in a common axial plane of the member 6, and in Fig. 1 each transverse pair of uppermost and lowermost ports lie in a common plane. In other words, the ports 13 and 14 are diametrically opposite to one another and posses the same porting area.

In the modification shown in Fig. 3 of the drawings, the same balanced porting is accomplished in a manner slightly different from that disclosed in Fig. 1. In that portion of the sleeve or member 6 to the left of the dotdash lines indicated at A, the openings or ports 17 in the upper Wall of the member are diametrically opposed to the ports 18 in the lower wall thereof. However, the sizes of these openings are not uniform, but they are so constructed that the porting areas of the openings 17 balance with the areas of the openings 18.

In that section of the sleeve or member 6 lying between the dot-dash lines A-B, it will be observed that the port 19 uppermost in the sleeve is considerably enlarged, but its area corresponds exactly with the combined porting areas of the openings 20 in the lower wall of the sleeve or member 6.

From the foregoing, it will be obvious that the ports in the sleeve or member 6 may vary in area so long as the combined total areas of the ports in the upper and lower walls respectively of the member are equal, and satisfactory results are attainable whether the ports are diametrically opposite to one another or not. It will be understood in the traverse of the shot column and powder wads forwardly past the ports, the propelling gases of explosion will be valved to the outside atmosphere through the upper and lower ports, said column and said wad establishing efliective seals of the ports in passing the same,

Therefore, the gases will be exhausted in sequential steps and, by the time the column reaches and enters the choke device, there will have been but slight lateral displace ment or digression from the axis of the column due to gas pressure within the column, to the end thatlittle or no work will have to be done by said choke device to return said digressed pellets to within the initial confines of said column.

What is claimed is:

l. A device for attachment to the forward end of the barrel of a shotgun for porting the gases of explosion received from said barrel upon firing, which comprises; a hollow tubular chamber to be coaxial with said barrel when attached at its inner end thereto and having an internal smooth tubular surface and a transverse cross section substantially greater than that of the bore of said barrel, thereby providing within said chamber an expansion space of substantially constant cross section for the shot column and gases travelling therethrough; said chamber having imperforate side walls over the length thereof; a first series of gas porting apertures disposed longitudinally in the top portion of the wall of said chamber; a second series of gas porting apertures disposed longitudinally in the bottom portion of the wall of said chamber; all of said apertures having their side Walls in planes normal to the longitudinal axis of said chamber, and their centers on the wall of said chamber disposed in the vertical axial plane of said chamber when the latter is attached to said barrel; the total gas porting areas of said first and second series of apertures being substantially equal.

2. A device for attachment to the forward end of the barrel of a gun for porting gases of explosion received from said barrel upon firing which comprises; a hollow tubular chamber to be coaxial with said barrel when attached at its inner end thereto and having an internal smooth tubular surface and a transverse cross section substantially greater than that of the bore of said barrel,

thereby providing within said chamber an expansion space of substantially constant cross section through which the shot column and gases travel, said chamber having imperforate side walls over the length thereof, a first series of gas porting apertures disposed in spaced relationship longitudinally in the top portion of the wall of said chamber, a second series of gas porting apertures disposed in spaced relationship longitudinally in the bottom portion of the wall of said chamber, the depth of the apertures of each series varying, and the total gas porting areas of 4 said first and second series of apertures being substantially equal.

3. A device for attachment to the forward end of the barrel of a gun for porting gases of explosion received from said barrel upon firing which comprises; a hollow tubular chamber to be coaxial with said barrel when attached at its inner end thereto and having an internal smooth tubular surface and a transverse cross section substantially greater than that of the bore of said barrel, thereby providing within said chamber an expansion space of substantially constant cross section for the shot column and gases travelling therethrough, a first series of gas porting apertures of varying depths disposed in spaced relationship longitudinally in the top portion of the wall of said chamber, a second series of gas porting apertures of varying depths disposed in spaced relationship longitudinally in the bottom portion of the wall of said chamber, and the total gas porting areas of said first and second series of apertures being substantially equal.

4. A device for attachment to the forward end of the barrel of a gun for porting gases of explosion received from said barrel upon firing, which comprises; a hollow tubular chamber to be coaxial with said barrel when attached thereto and having an internal smooth tubular surface and an internal diameter substantially greater than that of the bore of said barrel, thereby providing within said chamber an expansion space of substantially constant cross section for the shot column and gases travelling therethrough, said chamber having imperforate side walls over the length thereof, a gas porting aperture in the top portion of the wall of said chamber, a series of gas porting apertures disposed in spaced relationship longitudinally in the bottom portion of the wall of said chamber, and the depths of the gas porting areas of the top and bottom apertures being equal, the total area of the top gas porting aperture being equal to the total areas of the bottom series of gas porting apertures.

References Cited in the file of this patent UNITED STATES PATENTS 1,605,393 Cutts Nov. 2, 1926 1,773,260 Cutts Aug. 19, 1930 2,340,821 Russell Feb. 1, 1944 2,348,114 Dow May 2, 1944 2,453,121 Cutts Nov. 9, 1948 2,512,850 Crandall June 27, 1950 2,602,255 Cutts July 8, 1952 2,668,479 Batten Feb. 9, 1954 

